GB2260144A - Fabric control system for sewing machines - Google Patents

Abstract

A food mechanism for an elastric trim on a sowing machine comprising a driven member such as a conveyor belt (110) which accurately controls the movement of elastic trim to the needle (102). The conveyor may follow a device (10) for motoring and tensioning the trim and takes over control when the trim has been severed (at 122), the conveyor being driven from the device (10). The conveyor (110) may be incorporated in a device for folding fabric around the trip. As shown the conveyor belt (110) cooperates with a bed (112) but it may cooperate with a second belt instead. The belt may be replaced by a roller or feed dogs in alternative embodiments. <IMAGE>

Description

FABRIC CONTROL SYSTEMS The present invention relates to fabric control systems and more particularly to a control system for controlling the supply of elastic or other trim into a garment.

In a known apparatus described in our co-pending PCT patent application no. 01/00031 GB a metering system for control of the insertion of an elastic trim into a garment is disclosed. This arrangement is able to control the feeding of the elastic into the garment at a desired tension.

A problem arises however once the elastic has been trimmed or cut since the tension provided by the known apparatus is then released. With other types of trim it is useful to be able to control the feed of the trim until very close to the point of sewing.

It is an object of the present invention to provide a fabric control system which substantially overcomes the above problem and which is capable of controlling the supply of trim into a garment until virtually the last moment before the garment is sewn.

The present invention therefore provides a fabric control system comprising a driven member situated adjacent to a co-operating bed member, and being operative to control the movement of a fabric between the bed member and the driven member at the speed of the driven member.

In a preferred embodiment the driven member is a conveyor which driven by a remote drive from a metering unit to be thereby driven at a controlled ratio of speed to that of the metering unit. The ratio is preferably 1 to 1.

Alternatively the conveyor may be driven from an independent drive source.

The conveyor preferably is provided with means for raising the whole conveyor away from the bed member. This allows a free passage for elastic trim to be fed to the sewing point.

The invention also provides means for controlling the feeding of a trim within a folder.

Embodiments of the present invention will now be described, by way of example with reference to the accompanying drawings, in which: Figure 1 shows diagrammatically a fabric control system incorporating a driven feed member comprising a feed conveyor according to the present invention; Figure 2 shows diagrammatically a clamping arrangement for the system of Figure 1; Figure 3 shows diagrammatically in plan view a folder arrangement illustrating the position of the conveyor; Figure 4 shows diagrammatically the conveyor of Figure 1 illustrating the movements of the conveyor; Figure 5 shows diagrammatically the arrangement of Figure 3 illustrating one possible design of folder in end elevation.

Figure 6 -shows a prospective view from one side of a fabric control system according to the present invention; Figure 7 shows a view of the system of Figure 6 from the other side; and Figures 8 to 15 show alternative embodiments of the driven feed member configuration.

With reference now to Figure 1 of the drawings, the metering arrangement (meter) as described in the aforementioned co-pending PCT application is diagrammatically illustrated by box 10. As shown in Figure 2, meter 10 comprises two rollers 12,14 which can tension elastic 100 threaded therethrough, roller 12 being able to be driven in forward and reverse directions as indicated by arrow 16.

The sewing point for sewing the elastic trim 100 into a garment is indicated at 102 and this may be a twin needle arrangement in known manner.

Between the metering device 10 and front 102 is situated a driven conveyor 110. This conveyor may be driven by independent motor drive means (not shown) but in this embodiment is driven by a suitable output drive 18 from meter 10.

The conveyor 110 is preferably driven at an exact ratio to the speed of meter 10 and this is preferably 1 to 1 so that in use the conveyor when operative in a normal drive mode will convey elastic trim to the sewing point at the speed of the meter 10.

The conveyor co-operates with a bed member 112 on which the elastic trim 100 rests and thus the trim 100 is trapped between the bed 112 and conveyor 110. Conveyor 110 preferably comprises two end support rollers 114,116 with a driven belt 118 mounted therebetween to provide drive for the elastic trim 100. One or both of the rollers 114,116 may be driyen by a belt 120 (shown chain dotted) connected to output drive 18 on meter 10.

A guillotine device 122 is preferably included as shown between meter 10 and conveyor 110. This is a known device and is operative in known manner to sever the elastic trim at a time dictated by the meter control system which is operative to control meter 10.

In Figure 2 a clamp arrangement 124 is shown, this clamp being operative to clamp the elastic trim between the clamp roller 124 and a suitable co-operative pad 126 on meter 10 (thus pad 126 could be part of the external box member of meter 10.

This clamp when operated serves to prevent elastic trim 100 from falling away from meter 10 as might otherwise be the case when rollers 12,14 are opened.

In Figure 3 a folder 130 is diagrammatically shown, the folder comprising edge folding members 132,133 which fold over the edges of a fabric 134 to enfold elastic trim 100 therein. The trim and fabric are then sewn together at sewing points 102. Conveyor 110 is situated inbetween the edges 132,133 of folder 130 and is thus able to control the elastic trim until almost at the point where it is sewn into the garment at sewing points 102.

In Figure 5 it is shown that folder 130 has an open central portion 135 into which the co-operating bed 112 fits thus allowing elastic trim 100 to be moved without bearing onto the fabric 134.

The conveyor 110 is shown in Figure 4 and suitable mechanical/pneumatic means are provided to enable the conveyor to be lifted away from bed 112 as shown by arrows 140. Also the front edge of conveyor 112 can be lifted as shown by arrow 142. The rear end of conveyor 112 is preferably provided with spring means 144 operative in normal operation to press conveyor belt 118 down onto bed 112.

The operation of the system in a first embodiment is as follows however it is apparent that since the meter 10 and conveyor device 110 are independently operative other modes of operation are possible.

The garment fabric is assumed present at the meter 10 and is assumed to have elastic trim 10. The meter 10 feeds the elastic trim to conveyor 110 and this is then conveyed to the sewing point 102. The sewing machine then sews a predetermined number of stitches X (where X is between for example 0-99) to trap the elastic trim.

The conveyor 110 is then lifted to allow free passage of the elastic trim. The meter 10 reverses (as described in the aforementioned co-pending PCT application) and tension is applied to trim 100. The elastic trim is then sewn into the garment fabric as determined by the meter 10.

At the end of the sewing operation the conveyor 110 is lowered to grip the elastic 100.

The cutter 122 is then operated to cut the elastic trim on the far side to the sewing point 102. The meter rollers 12,14 then open and clamp roller 124 is operated.

Thus elastic trim 100 is trapped ready for the next operation.

The cut elastic trim is now under the control of driven conveyor 110 and this is driven, preferably at a 1 to 1 ratio from meter 10 at the same speed as rollers 12,14 were previously driven.

Thus the elastic trim is retained until almost the last right up until the sewing point 102 or until a desired release point prior to the elastic emerging from conveyor 110.

In a preferred embodiment the whole conveyor 110 and meter 10 are operable by a pneumatic lift in the direction of arrow 11 (Figure 1) to clear the folder thus allowing threading of the fabric 134 into the folder 130.

The driven conveyor 110 thus provides a positive drive for elastic trim 100 thus maintaining exact tension until the trim almost reaches sewing point 102.

With reference now to Figures 6 and 7 a practical arrangement is shown. Reference numerals indicate those parts which perform the same or similar functions to those described in relation to Figures 1 and 5.

With reference now to Figure 8, the bed member 112 is replaced by a further conveyor 114',116',118'. This is particularly useful if the trim is a delicate material such as lace which might otherwise be distorted by a static bed member.

With reference to Figure 9, the conveyor arrangement 114,116,118 may be replaced by a driven wheel member 300.

This may be driven by any suitable means such as a direct drive or by a drive taken from a metering unit such as 10.

With reference to Figure 10 the wheel 302 could be toothed and could be driven by a stepping motor 304 via a toothed belt 306 providing exact control over the trim feed. Other drive arrangements are obviously possible.

With reference now to Figures 11 and 12, the conveyor arrangements 110 may extend up to or as shown past the sewing points 102.

The belt 118 is extended in length to pass between the two points 102. The bed member 112' is preferably shorter than conveyor 114,116,118 since the bed of the sewing machine will provide the necessary bed for the conveyor at or close to the sewing point 102.

Where it is not required to pre-tension for example elastic trim by means of for example a metering unit 10 the driven members 110,300 or 302 etc could be used alone to control accurately the feeding of trim into a sewing machine. The conveyor or other driven members could be replaced by a friction member which bears down on to a suitable plate or bottom conveyor. This enables trim to be controlled within the folder 130 to be fed accurately to the sewing point. Conveyor 110 could thus be friction controlled as could wheel 300 to provide control for the trim within the folder 130.

With reference now to Figures 13 to 15 the driven feed member could be a feed dog assembly 400 suitably driven in a reciprocating manner.

The feed dog assembly preferably comprises two (or more) feed dogs 402,404 which as indicated by arrows 406,408 are driven in opposition to each other. Thus as one feeds forward to feed trim to the sewing points 102 the other moves backwards to a position at the rear where it can then provide forward motion.

The teeth 410 on each dog are shaped (Figure 14) to have a vertical front edge and to slope at the back to thereby provide grip for the trim 100 in the forward direction of movement 408 and to slide over the trim in the rearward direction 406.

The dogs 402,404 are spring urged by suitable compression springs 420,422,424 towards the bed plate member 112. Reciprocating motion for dogs 402,404 is provided by known mechanism (not shown) as used in sewing machine engineering.

Claims (13)

1. A fabric control system comprising a driven member situated adjacent to a co-operating bed member, and being operative to control the movement of a fabric between the bed member and the driven member at the speed of the driven member.

2. A fabric control system as claimed in claim 1 in which the driven member is a conveyor which is driven by a remote drive from a metering unit to be thereby driven at a controlled ratio of speed to that of the metering unit.

3. A fabric control system as claimed in claim 2 in which the ratio of speed is 1 to 1.

4. A fabric control system as claimed in claim 1 in which the conveyor is driven from an independent drive source to the metering unit drive.

5. A fabric control system as claimed in any one of the claims 2 to 4 in which the conveyor is provided with means for raising the whole conveyor away from the bed member to allow a free passage for elastic trim to be fed to a sewing point.

6. A fabric control system as claimed in any one of claims 1 to 5 in which the fabric control system provides means for controlling the feeding of a trim within a folder.

7. A fabric control system as claimed in claim 6 in which the folder comprises a flat plate for supporting the trim, the flat plate comprising the bed member.

8. A fabric control system as claimed in claim 5 in which a clamp member is provided adjacent to the conveyor and is separately operable to clamp the elastic trim to prevent the elastic trim from falling away from the meter unit.

9. A fabric control system as claimed in claim 8 in which the clamp member comprises a clamp roller and a suitable cooperative pad.

10. A fabric control system as claimed in claim 9 in which the clamp member is normally operated to allow free passage of the elastic trim between the clamp roller and the cooperative pad.

11. A fabric control system as claimed in claim 10 in which the metering unit comprises two rotatable metering rollers and in which the rollers are mounted to be separable by a distance to allow free movement of an elastic trim therebetween and in which the clamp means is operative to clamp the elastic trim only when the metering rollers are separated to allow free movement of the elastic trim.

12. A fabric control system as claimed in any one of claims 8 to 11 in which the conveyor is positioned between the metering unit and the needle position of a sewing machine.

13. A fabric control system substantially as described with reference to the accompanying drawings.